The trend toward networking, for example, of closed- and/or open-loop control devices in modern motor vehicles is making possible increasingly capable diagnostic methods with which, for example, fault states in the motor vehicle can be detected. Electronic motor vehicle diagnostic systems are used in modern service facilities to allow unequivocal fault diagnosis by service technicians, especially including service technicians who do not have detailed knowledge of the logical and physical networking of the individual components in the particular motor vehicle. A large number of manufacturer-specific motor vehicle diagnostic systems exist. There are also manufacturer-independent motor vehicle diagnostic systems that have a very wide variety of mechanisms for fault diagnosis for a broad range of motor vehicles. For that purpose, vehicle- or manufacturer-specific diagnostic mechanisms and/or diagnostic parameters are stored in the motor vehicle diagnostic systems. In addition, the known motor vehicle diagnostic systems have a user interface that is generally embodied in the form of a screen and a keyboard. The current motor vehicle diagnostic systems are moreover equipped with different motor vehicle adapters so that a suitable connection can be made to the motor vehicle. If this connection is a cable-based connection, the corresponding motor vehicle must be located in the physical vicinity of the motor vehicle diagnostic system.
German Patent No. 44 46 512 discloses an apparatus for carrying out vehicle tests in which the terminal of the motor-vehicle-side diagnostic/test connector is connected to a motor vehicle diagnostic system present in the service facility not via a cable but rather via a telephone located in the motor vehicle itself, so that transfer of the diagnostic data can be performed via the mobile radio network.
German Published Patent Application No. 199 21 846 discloses an external portable test unit that is equipped with a modem and is connected to a mobile telephone so that faults can be diagnosed and malfunctions remedied outside permanent service facilities via corresponding mobile radio connections.
In the disclosed systems, the diagnostic mechanisms and/or diagnostic parameters that are employed to determine diagnostic data are stored permanently in the vehicle and/or in the service center or the vehicle diagnostic system. Expansion of the diagnostic mechanisms and/or diagnostic parameters, which is necessary, e.g., when new vehicle components are utilized, is therefore laborious.